Cold plasma shields

[Sarevok]

I heard that cold plasma can be used create a "second skin" essentialy forming a star trek style shield. Could someone explain what cold plasma realy is and what are the limitations of cold plasma shields ?

[jegs2]

I heard that cold plasma can be used create a "second skin" essentialy forming a star trek style shield. Could someone explain what cold plasma realy is and what are the limitations of cold plasma shields ?

Cold plasma?

[Morat]

The purpose of cold plasma shielding is to absorb incoming energy. It is essentially an anti-radar technology. It has about as much in common with Star Trek shields as black paint has with Culture stealth fields.

[Admiral Valdemar]

Morat hit the nail on the head so I'll just hammer it in, cold plasma is an alternate form of stealth technology that was supposedly being tested on Russian aircraft. It is able to work on most planes without any special airframe design, most aeroplanes with this generator will be able to become less susceptible to RADAR detection as the cloud of ionised gas absorbs radio waves.

[Kuroneko]

Morat hit the nail on the head so I'll just hammer it in, cold plasma is an alternate form of stealth technology that was supposedly being tested on Russian aircraft. It is able to work on most planes without any special airframe design, most aeroplanes with this generator will be able to become less susceptible to RADAR detection as the cloud of ionised gas absorbs radio waves.

The effect is on any EM radiation below the plasma frequency, which is dependent on density. It only works on radar because there is no feasible way to confine it in a dense enough state around the aircraft.

[jegs2]

The effect is on any EM radiation below the plasma frequency, which is dependent on density. It only works on radar because there is no feasible way to confine it in a dense enough state around the aircraft.

That does sound somewhat like the technobabble I've heard about ST shields. Does anyone think, based on this cold plasma gizmo, that we're any closer to developing ST-type shields?

[Kuroneko]

That does sound somewhat like the technobabble I've heard about ST shields. Does anyone think, based on this cold plasma gizmo, that we're any closer to developing ST-type shields?

The plasma frequency is merely the frequency of EM radiation above which the plasma permits the radiation, and below which it does not. It is proportional to the square root of the density of free electrons. This is the reason one can bounce low-frequency radio waves off the Earth's ionosphere. It has absolutely nothing to do with Trek.

[Luke Starkiller]

That does sound somewhat like the technobabble I've heard about ST shields. Does anyone think, based on this cold plasma gizmo, that we're any closer to developing ST-type shields?

The plasma frequency is merely the frequency of EM radiation above which the plasma permits the radiation, and below which it does not. It is proportional to the square root of the density of free electrons. This is the reason one can bounce low-frequency radio waves off the Earth's ionosphere. It has absolutely nothing to do with Trek.

But a higher desnsity would permit the plasma to block higher frequencies, Lasers etc. correct? I think that is what jegs2 is getting at.

[Kuroneko]

The plasma frequency is merely the frequency of EM radiation above which the plasma permits the radiation, and below which it does not. It is proportional to the square root of the density of free electrons. This is the reason one can bounce low-frequency radio waves off the Earth's ionosphere. It has absolutely nothing to do with Trek.

But a higher desnsity would permit the plasma to block higher frequencies, Lasers etc. correct?

Correct. But achieving that density, particularly on the hull of a ship, is the real problem.

I think that is what jegs2 is getting at.

Oh. I thought he was referring to the underlying mechanism itself (Trek explanations have no semantic content). Even at higher densities, it is still short of the effects of Trek deflector shields, though.

[Beowulf]

It also has the problem of being a double blind. You can have stealth, but you can't turn on your radar, or use a radio w/ a freq below that of the radar.

[kojikun]

Wouldnt the same signal blocking effect be the cause of reentry blackouts with spacecraft? i do believe the air around the reentry capsule/shuttle ionizes.

[Kuroneko]

Wouldnt the same signal blocking effect be the cause of reentry blackouts with spacecraft? i do believe the air around the reentry capsule/shuttle ionizes.

Indeed. There is a radio blackout period during reentry, or at least would be if the TDRSS (tracking and data relay satellite system) wasn't there. The air is only ionized to a significant enough degree on one side of the spaceshuttle; in the outward direction radio communication is still possible.